A brake disc structure is disclosed in TW Patent No. I312392 and contains a first disc and a second disc, wherein the first disc is made of iron, and the second disc is made of aluminum alloy.
A disk brake rotor is disclosed in U.S. Pat. No. 8,522,931B2 and includes a first rotor portion, a second rotor portion and a third rotor portion. The second rotor portion has an annular portion and at least one ventilation hole. The third rotor portion also has an annular portion. The first portion is attached to and disposed between the second rotor portion and the third rotor portions, such that a surface of the first rotor portion is an exposed area exposed by the at least one ventilation hole. The first rotor portion is made of aluminum or aluminum alloy, and the second and third rotor portions are made of stainless steel. The exposed area of the first rotor portion is not supported by the second and third rotor portions, so the first rotor portion is broken and deformed easily after a period of using time.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.